target-arm: implement IRQ/FIQ routing to Monitor mode

SCR.{IRQ/FIQ} bits allow to route IRQ/FIQ exceptions to monitor CPU
mode. When taking IRQ exception to monitor mode FIQ exception is
additionally masked.

Signed-off-by: Sergey Fedorov <s.fedorov@samsung.com>
Signed-off-by: Fabian Aggeler <aggelerf@ethz.ch>
Signed-off-by: Greg Bellows <greg.bellows@linaro.org>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1416242878-876-10-git-send-email-greg.bellows@linaro.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

diff --git a/target-arm/helper.c b/target-arm/helper.c
index d3180ddbce57a8203bba0658f8ad805e7e11ba07..973b5a90967b4f03bc67256e066a74a52f6a9c0d 100644 (file)
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -4233,12 +4233,21 @@ void arm_cpu_do_interrupt(CPUState *cs)
         /* Disable IRQ and imprecise data aborts.  */
         mask = CPSR_A | CPSR_I;
         offset = 4;
+        if (env->cp15.scr_el3 & SCR_IRQ) {
+            /* IRQ routed to monitor mode */
+            new_mode = ARM_CPU_MODE_MON;
+            mask |= CPSR_F;
+        }
         break;
     case EXCP_FIQ:
         new_mode = ARM_CPU_MODE_FIQ;
         addr = 0x1c;
         /* Disable FIQ, IRQ and imprecise data aborts.  */
         mask = CPSR_A | CPSR_I | CPSR_F;
+        if (env->cp15.scr_el3 & SCR_FIQ) {
+            /* FIQ routed to monitor mode */
+            new_mode = ARM_CPU_MODE_MON;
+        }
         offset = 4;
         break;
     case EXCP_SMC: